Surfactant deficiency in full-term newborns with transient tachypnea delivered by elective C-section

Predictors of successful treatment of respiratory distress with aerosolized calfactant

INTRODUCTION

Predictors for successful aerosolized surfactant treatment are not well defined.

OBJECTIVE

To identify predictors for successful treatment in the AERO-02 trial and the AERO-03 expanded access program.

METHODS

Neonates receiving nasal continuous positive airway pressure (NCPAP) at the time of first aerosolized calfactant administration were included in this analysis. Associations between demographic and clinical predictors to need for intubation were examined using univariate testing and multivariate logistic regression analyses.

RESULTS

Three hundred and eighty infants were included in the study. Overall, 24% required rescue by intubation. Multivariate modeling revealed that the predictors of successful treatment were a gestational age ≥31 weeks, a respiratory severity score (RSS) of <1.9, and <2 previous aerosol treatments.

CONCLUSION

Gestational age, number of aerosols, and RSS are predictive of successful treatment. These criteria will help select patients most likely to benefit from aerosolized surfactant.

Can surfactants affect mortality and morbidity in term infants with respiratory failure?

BACKGROUND

We aimed to discuss term infants who are given surfactant due to respiratory disorder according to the underlying etiology, the dose of surfactant administration, and the need for repeated surfactant administration.

METHODS

In this retrospective study infants hospitalized in the 4th level neonatal intensive care unit during January 2019 and December 2021 and administered surfactant due to respiratory distress were included. Term infants given surfactant due to respiratory failure were included in the study through the data recording system. The number of surfactant doses, indications for administration, mortality, duration of hospitalization, intubation time, and inotrope use were recorded in the infants included in the study.

RESULTS

: During the two-year period, 1250 infants were hospitalized in our neonatal intensive care unit. Of those, 56 infants received surfactant replacement therapy for severe respiratory failure. There were 30 infants with pneumonia, 4 infants with meconium aspiration syndrome (MAS), and 22 infants with transient tachypnea of the newborn (TTN). It was seen that single-dose administration was higher in patients with TTN (p = 0.01), while multiple-dose surfactant administration was more common in patients with MAS, resulting in a statistical difference (p = 0.02). Mortality was lower, especially in cases given early surfactant administration and this situation was statistically significant (p < 0.001). Duration of intubation was 5.05 ± 4.7 days in early surfactant administration group and 8.0 ± 6.1 days in late surfactant administration group. This difference was statistically significant (p = 0.04). While early surfactant application was statistically higher in the TTN group (p = 0.007), late surfactant application was statistically higher in the pneumonia group (p = 0.001).

DISCUSSION

Despite the difference on administration time and repeat dose interval due to etiology, surfactant treatment is improving the respiratory distress of term infants.

Wet lung leading to RDS: the lung ultrasound findings and possible mechanisms - a pilot study from an animal mode

BACKGROUND

Clinically, the lung ultrasound (LUS) showed wet lung could cause respiratory distress syndrome (RDS) in newborns. This work aimed to investigate LUS changes over time and its potential mechanism as alveolar fluid increase in a rabbit model.

METHODS

A total of 35 New Zealand Rabbits were randomly assigned to seven groups. Models of various alveolar fluid levels were induced by infusion of different volumes of normal saline (NS) via the endotracheal tube. LUS was performed before NS infusion, immediately after NS infusion and 4 h after NS infusion. To appraise LUS changes and its potential mechanism as alveolar fluid increase, histopathological examination, the mRNA and protein expression of surfactant protein (SP), and immunohistochemistry (IHC) were performed. The expression levels of SP-B and SP-C proteins were detected using western blotting, and the relative expression levels of SP-B and SP-C mRNA were detected using qRT-PCR.

RESULTS

The results showed that LUS changed from B-line to lung consolidations accompanied by air-bronchograms in some locations of lungs at 4 h when the injection volume ≥ 6 ml/kg. Histopathological examination showed alveoli collapse, inflammatory cell infiltration and alveolar wall thickened. SP-B and SP-C mRNA and protein expression were statistically significantly reduced when the injection volume ≥6 ml/kg (p < .05). IHC staining displayed the same findings.

CONCLUSIONS

As alveolar fluid increase, LUS changed from wet lung to RDS after 4 h. The possible mechanism was that the SP protein expression was significantly reduced. LUS can be used to guide the administration of exogenous surfactant in this situation.

Rapid diagnosis of respiratory distress syndrome by oral aspirate in premature newborns

OBJECTIVE

The stable microbubble test on gastric aspirate and on amniotic fluid has been used for the diagnosis of respiratory distress syndrome in the newborn. However, no study has performed this test on oral aspirates from premature infants. The objective of this study was to evaluate the performance of the stable microbubble test on oral aspirates from preterm newborns to predict respiratory distress syndrome.

METHOD

This study included infants with gestational age <34 weeks. Oral fluids were obtained immediately after birth and gastric fluids were collected within the first 30 minutes of life. The samples were frozen and tested within 72 hours.

RESULTS

The sample was composed of paired aspirates from 64 newborns, who were divided into two groups: respiratory distress syndrome group (n=21) and control group (n=43). The median (interquartile range) of the stable microbubble count in the oral samples of infants with respiratory distress syndrome was significantly lower than that of infants who did not develop respiratory symptoms: respiratory distress syndrome group=12 (8-22) stable microbubbles/mm²; control group=100 (48-230)microbubbles/mm² (p<0.001). The correlation between microbubble count in gastric and oral aspirates was 0.90 (95% confidence interval=0.85-0.95; p<0.001). Considering a cut-off point of 25microbubbles/mm², the sensitivity and the specificity of the stable microbubble test were 81.4% and 85.7%, respectively.

CONCLUSION

The study suggests that the stable microbubble test performed on oral aspirate is a reliable alternative to that performed on gastric fluid for the prediction of respiratory distress syndrome in the newborn.

Birth delivery method affects expression of immune genes in lung and jejunum tissue of neonatal beef calves

Background

Caesarean section is a routine veterinary obstetrical procedure employed to alleviate dystocia in cattle. However, CS, particularly before the onset of labour, is known to negatively affect neonatal respiration and metabolic adaptation in humans, though there is little published information for cattle. The aim of this study was to investigate the effect of elective caesarean section (ECS) or normal trans-vaginal (TV) delivery, on lung and jejunal gene expression profiles of neonatal calves.

Results

Paternal half-sib Angus calves (gestation length 278 + 1.8 d) were delivered either transvaginally (TV; n = 8) or by elective caesarean section (ECS; n = 9) and immediately euthanized. Lung and jejunum epithelial tissue was isolated and snap frozen. Total RNA was extracted using Trizol reagent and reverse transcribed to generate cDNA. For lung tissue, primers were designed to target genes involved in immunity, surfactant production, cellular detoxification, membrane transport and mucin production. Primers for jejunum tissue were chosen to target mucin production, immunoglobulin uptake, cortisol reaction and membrane trafficking. Quantitative real-time PCR reactions were performed and data were statistically analysed using mixed models ANOVA. In lung tissue the expression of five genes were affected (p < 0.05) by delivery method. Four of these genes were present at lower (LAP, CYP1A1, SCN11α and SCN11β) and one (MUC5AC) at higher abundance in ECS compared with TV calves. In jejunal tissue, expression of TNFα, Il-1β and 1 l-6 was higher in ECS compared with TV calves.

Conclusions

This novel study shows that ECS delivery affects the expression of key genes involved in the efficiency of the pulmonary liquid to air transition at birth, and may lead to an increased inflammatory response in jejunal tissue, which could compromise colostral immunoglobulin absorption. These findings are important to our understanding of the viability and management of neonatal calves born through ECS.

Common respiratory conditions of the newborn

KEY POINTS

Respiratory distress is a common presenting feature among newborn infants.Prompt investigation to ascertain the underlying diagnosis and appropriate subsequent management is important to improve outcomes.Many of the underlying causes of respiratory distress in a newborn are unique to this age group.A chest radiograph is crucial to assist in diagnosis of an underlying cause.

EDUCATIONAL AIMS

To inform readers of the common respiratory problems encountered in neonatology and the evidence-based management of these conditions.To enable readers to develop a framework for diagnosis of an infant with respiratory distress. The first hours and days of life are of crucial importance for the newborn infant as the infant adapts to the extra-uterine environment. The newborn infant is vulnerable to a range of respiratory diseases, many unique to this period of early life as the developing fluid-filled fetal lungs adapt to the extrauterine environment. The clinical signs of respiratory distress are important to recognise and further investigate, to identify the underlying cause. The epidemiology, diagnostic features and management of common neonatal respiratory conditions are covered in this review article aimed at all healthcare professionals who come into contact with newborn infants.